DEFRA
WR1120:
BASELINE WORK FOR REVISED ENVIRONMENTAL
PERMITTING REGULATIONS: WASTES SPREAD TO
LAND
WRc Ref: DEFRA8242
MAY 2010
WR1120:
BASELINE WORK FOR REVISED ENVIRONMENTAL PERMITTING
REGULATIONS: WASTES SPREAD TO LAND
WRc Report No.:
DEFRA8242
Date:
May 2010
Authors:
James Peacock, Victoria Benson and Jane Turrell
Contract Manager: James Peacock
Contract No.:
15419-0
Any enquiries relating to this report should be referred to the authors at the following address:
WRc Swindon,
Frankland Road, Blagrove,
Swindon, Wiltshire, SN5 8YF.
Telephone: + 44 (0) 1793 865000
Fax: + 44 (0) 1793 865001
Website:
www.wrcplc.co.uk
The contents of this document are subject to copyright and all rights are reserved. No part of
this document may be reproduced, stored in a retrieval system or transmitted, in any form or
by any means electronic, mechanical, photocopying, recording or otherwise, without the prior
written consent of the copyright owner.
This document has been produced by WRc plc.
CONTENTS
1.
INTRODUCTION
1
2.
METHODOLOGY
3
2.1
2.2
Extracting information
Identify risks
3
3
3.
RESULTS
5
3.1
3.2
3.3
Assessment of exemption notifications
Literature review
Risk Scoring
5
6
11
4.
CONCLUSIONS
17
REFERENCES
19
APPENDICES
APPENDIX A
APPENDIX B
METHODOLOGY FOR ASSESSING IMPACTS AND
PRIORITISING HIGH RISK WASTES
DATA SUMMARIES FOR WASTE CATEGORIES
27
33
LIST OF TABLES
Table 1.1
Table 3.1
Table 3.2
Table 3.3
Table 3.4
Waste materials to be considered for assessment of environmental
impacts
Number of exemption notifications available for each waste material
Waste materials to be considered for assessment of environmental
impacts
Waste materials to be considered for assessment of environmental
impacts
Comparison of risk scores between wastes applied under EPR 2007
Regulations and EPR 2009 Regulations
1
5
12
14
15
Defra
1.
INTRODUCTION
Waste materials have been applied to agricultural soils for many decades. Waste materials
can confer many benefits to agricultural soil, which are principally adding nutrients essential
for plant growth, adding organic carbon for improved soil structure, and altering pH of the soil
to give optimum growing conditions. Spreading waste to agricultural land has the benefit of
diverting waste that would have otherwise be destined for landfill.
Although there are obvious benefits of applying waste to land, the activity is not without risk to
the environment and human health, it is therefore currently controlled by the Environment
Agency under the terms of the Waste Framework Directive (2006/12/EC).
Up to April 2010, the majority of wastes applied to land had been carried out under exemption
from Environmental Permitting. From April 2010, the Environmental Permitting Regulations
2009 came into force, which introduced substantial changes to the way waste to land is
managed. Many of the higher risk wastes are now regulated under standard permits.
However, a number of ‘lower risk’ waste materials can still be applied under an exemption.
Following work carried out for project WR1103, Defra wished to assess the wastes being
spread to land under the revised Environmental Permitting Regulations 2009 (EPR2009) in
terms of the risks and benefits in their application to land. The categories of waste materials
for consideration are given in Table 1.1.
Table 1.1
Waste materials to be considered for assessment of environmental
impacts
List of wastes code
Waste Description
010102, 010408, 170504
Chalk only
020106
Farmyard and horse manure only
020202
Shellfish shells from which the soft tissue or flesh has been
removed only
020399, 020401
Soil from cleaning and washing fruit and vegetables only
100101
Ash from wood chip boilers produced pursuant to an operation
described in the paragraph numbered U4 in this Chapter only
170506
Dredging spoil (other than those mentioned in 170505)
generated from the creation or maintenance of habitats,
ditches or ponds within parks, gardens, fields and forests only
020199
Spent compost from the growing of mushrooms only
190599
Compost produced pursuant to a treatment described in the
paragraph numbered T23 or T26 of Chapter 2 only
190604
Digestate produced pursuant to a treatment described in the
paragraph numbered T24 or T25 of Chapter 2 only
WRc Ref: DEFRA8242/15419-0
May 2010
1
Defra
List of wastes code
Waste Description
190812
Waste consisting of biobed or biofilter material produced
pursuant to a treatment described in the paragraph numbered
T32 of Chapter 2 only
200108
Coffee grounds only
020199
Milk from agricultural premises only.
As with the previous Defra project WR1103, details on the characteristics and loading rates of
these waste materials were obtained from notification forms for paragraph 7 exemptions. For
this project, notifications for applying waste to land were obtained for the period November
2008 – November 2009, and amalgamated with data collected for project WR1103 (July 2007
– July 2008). This gave two full years worth of data on the application of these materials to
land in England and Wales.
From the notifications, it would appear that a number of these waste materials are only spread
in very small amounts in the UK, and in some cases there are no notifications for the materials
to be spread to land under a paragraph 7 exemption.
In this report, data on each waste material has been compiled, and ranked against all wastes
applied to land under paragraph 7. The general properties of the waste materials are
discussed, and data collected from paragraph 7 notification forms and other sources
presented.
WRc Ref: DEFRA8242/15419-0
May 2010
2
Defra
2.
METHODOLOGY
2.1
Extracting information
The Environment Agency‘s database was queried using the List of Waste/European Waste
Catalogue code in order to obtain notifications specific to the wastes listed.
Due to the way the notifications are stored on the system, it was not possible to obtain a
detailed description of the waste type being applied for until the above List was obtained. WRc
therefore requested from the Environment Agency (EA) all applications with List of Waste
(LoW) codes matching those in Table 1.1. As the waste types being investigated were more
specific than LoW categories, it was necessary to look at all the application forms for the listed
European Waste Catalogue (EWC) codes to identify the sub-set that were required.
Once the notifications were obtained from the EA, the following information could be extracted
from the notifications:




Detailed description of waste being applied.
Where it is being applied, including the national grid reference (NGR).
Amount of waste being applied, application rate and whether it is being applied in
conjunction with any other wastes.
Waste characteristics data including (where available) major nutrients, metals, pH, dry
matter, organic content and any other trace contaminant/nutrient data.
This data was entered into the database generated under the previous Defra project,
WR1103.
Where insufficient data was available on a specific waste stream, a brief literature review was
conducted. This was necessary for a number of waste materials where no information was
available from exemption notifications (as discussed in Section 3). The literature was
searched for compositional data; information on how the material is spread to land and
justifications in terms of agricultural benefit. Table 3.1 shows the number of exemption
applications that were available for each waste type.
2.2
Identify risks
On completion of the data collection exercise and the literature review, risk scores were
derived for each waste material. This was undertaken using the same risk assessment
methodology used for the previous Defra project, WR1103. The methodology is reproduced in
Appendix A. Once the risk score had been derived, this was then compared with wastes from
project WR1103.
WRc Ref: DEFRA8242/15419-0
May 2010
3
Defra
WRc Ref: DEFRA8242/15419-0
May 2010
4
Defra
3.
RESULTS
3.1
Assessment of exemption notifications
Table 3.1 lists the number of exemption notifications available for the assessment.
Table 3.1
Number of exemption notifications available for each waste material
Number of notification
forms available
Waste material
0 – supplemented with data
from Defra project WQ0206
Farmyard and horse manure only
Compost produced pursuant to a treatment described in the
paragraph numbered T23 or T26 of Chapter 2 only
65
Digestate produced pursuant to a treatment described in the
paragraph numbered T24 or T25 of Chapter 2 only
15
Soil from cleaning and washing fruit and vegetables only
34
Spent compost from the growing of mushrooms only
0
Milk from agricultural premises only
18
Chalk only
0
Ash from wood chip boilers produced pursuant to an operation
described in the paragraph numbered U4 in this Chapter only
0
Dredging spoil (other than those mentioned in 170505)
generated from the creation or maintenance of habitats, ditches
or ponds within parks, gardens, fields and forests only
7
Coffee grounds only
11
Shellfish shells from which the soft tissue or flesh has been
removed only
0
Waste consisting of biobed or biofilter material produced
pursuant to a treatment described in the paragraph numbered
T32 of Chapter 2 only*
0*
*Biobed material is currently applied to land under a paragraph 16 exemption, where there is no
requirement to test waste being applied to land
There was no data available from the exemption notifications on manure; mushroom compost;
chalk; ash from wood chip boilers; shellfish shells or biobed waste and risk scores were
therefore derived from literature review data. This does not conclude that this material is not
applied to land for agricultural benefit; the reasons for lack of notification forms are discussed
below. General characteristics of each material are also discussed, along with reported
agronomic benefits and environmental impacts.
WRc Ref: DEFRA8242/15419-0
May 2010
5
Defra
3.2
Literature review
3.2.1
010102, 010408, 170504 Chalk only
Chalk can be applied to land where the acidity of soil requires correction. Chalk has a
neutralising value (NV) of 50-55% of pure lime (RB209), indicating it would need to be applied
at 1.8-2 times the rate of lime to achieve the same change in soil pH. The Fertiliser Handbook
(RB209) provides guidance on the amounts of liming material that must be applied to different
soil types and different pHs. This guidance should be followed when applying chalk to land.
Waste calcium carbonate is produced by the fertiliser industry in the manufacture of
ammonium sulphate (Dass, 1993), from quarrying and in cement production.
No notifications were found relating to the spreading of waste chalk to agricultural land. This
may have been because operators do not consider the chalk a waste material. Waste from
mines and quarries only became a controlled waste in 2006 (under The Waste Management
(England and Wales) Regulations 2006), and therefore considering implications of waste
regulations may be new for many operators.
Contamination of chalk will depend on the source, although natural chalk waste should be free
of trace metal contaminants. Calcium carbonate generated by the chemical processing
industry may contain other contaminants specific to the process from which it was generated.
3.2.2
020106 Farmyard and horse manure only
Farmyard and horse manure is not considered a waste material (ECJ Case C-416/02) under
the terms of the Waste Framework Directive when used as a soil fertiliser, and there is
therefore no need to obtain an exemption from Environmental Permitting. However, an
exemption has been maintained as ―Defra cannot exclude the possibility that there may be
some circumstances in which manure/slurry is classified as waste either in relation to its
storage or its use as a soil fertiliser – i.e. land treatment resulting in benefit to agriculture.‖
This exemption is therefore not widely used, and indeed it was found that very few paragraph
7 exemptions had been registered for this use.
Animal manures are principally derived from cattle, poultry, pigs and sheep and are in the
form of either liquid slurries or more solid manures. These materials consist of animal faeces
and urine mixed with bedding material (typically straw). They are usually rich in readily
available N from the urine and have been applied to agricultural land principally as a fertiliser
to supply N, P and K. Guidance on the nutrient content and how to apply animal manures is
given in Defra‘s Fertiliser Handbook (RB209).
The majority of organic matter in manures and slurries is not considered to be highly
biodegradable as it comprises material that has already been through a decomposition
process in the animal gut. However, a proportion of the carbon in manures is in the form of
volatile solids (VS) and these compounds are precursors of emissions of methane (CH 4) and
non-methane volatile organic compounds (NMVOCs) and may also be a source of
metabolizable carbon for soil microbes. Manures are increasingly being considered as a
feedstock for anaerobic digestion which would lead to changes in the characteristics of
resulting digestate, in particular the reduction in the proportion of C as VS due to microbial
breakdown of VS to CH4.
WRc Ref: DEFRA8242/15419-0
May 2010
6
Defra
Total livestock manure applied to land in the UK on an annual basis is estimated at 90.7
million tonnes fresh weight (15.7 million tonnes dry weight) (Humphries et al. 2007), compared
to 8 million tonnes fresh weight of all waste spread under paragraph 7 exemptions in England
and Wales (WRc, 2009). This shows that large amounts of manure are being applied to land
outside of the exemption regime.
Animal manures do not have the same requirements for treatment prior to application to land
as do other animal by-products. Animal manures can be applied to land with minimal
treatment, and therefore there is some residual risk of the spread of animal pathogens. It is
therefore important to observe good agricultural practice when applying these materials in
order to mitigate any potential risk from pathogens.
3.2.3
020199 Spent compost from the growing of mushrooms only
Defra have produced a number of papers pertinent to growing media and soil improvers since
1999, including monitoring and assessment of spent mushroom compost as a soil improver
[68, 46, 103]. The UN training manual for mushroom growing also includes a section on
recycling the spent compost to other applications [65]. Individual papers such as 60, 61, 63,
64 and 66 all look at the benefits of spent mushroom compost for various applications. Paper
66 talks exclusively about spent mushroom compost and its benefits, properties and scientific
backing.
Mushroom compost can contain many types of manure, gypsum (to raise pH) and may also
contain added inorganic nutrients. Mushroom compost also typically contains 15-30% peat.
Mushroom compost is likely to contain similar levels of metals to composted manure, as this is
the bulk input to the mushroom compost. Levels of nutrients will differ from compost. In some
cases nitrogen, phosphate and potassium (NPK) fertilisers are added to the compost before it
is sold on to end users.
3
Total supply is estimated to be approximately 280,000 m per year which places spent
mushroom compost second to bark as the most significant alternative to peat. The
landscaping sector is the largest single user of mushroom compost, accounting for 68% of the
total market for spent mushroom compost.
Mushroom compost may contain traces of fungicides used to treat fungal competitors to the
mushrooms, although it is generally low in other organics as mushrooms are generally
intolerant to chemicals.
3.2.4
020202 Shellfish shells from which the soft tissue or flesh has been removed
only
As an animal by-product, shellfish shells are subject to the Animal By-product Regulations,
which specify the treatment requirements for the material prior to being applied to land, to
remove any pathogens present in the waste.
Shellfish shells have a high proportion of CaCO 3, and indeed have a very similar liming
potential to pure CaCO3 [109]. One potential obstacle is the residual salt (NaCl) contamination
on the shells, which may affect some crops, but is unlikely to leach to controlled waters in
sufficient concentrations to cause pollution. Similar controls are placed on shellfish shells as
are currently applied to general fish waste.
WRc Ref: DEFRA8242/15419-0
May 2010
7
Defra
SEAFISH appear to have undertaken the majority of the research into land-spreading shellfish
waste. A report by Defra [30] describes the overall impact of the fish and shellfish industry
including a lifecycle assessment but it does not contain much information on disposal options.
ADAS undertook a study for SEAFISH [31] which looked at the disposal and treatment options
for waste shellfish including the agricultural benefit and composition of the waste applied to
land. Shellfish cannot be applied to land without pre-treatment; composting, anaerobic
digestion and rendering are the predominant forms of treatment (SEAFISH [27, 29, 51]). The
autoclaving guidance from SEAFISH [27] reports that it is difficult to sufficiently clean shellfish
shells for other notifications and this means most shellfish waste is primarily dealt with whole
(i.e. with residual organic matter still attached). Further information on the composting of
waste has been developed by the Compost Council of Canada Symposium and the Irish Sea
Fisheries Board [25, 28].
3.2.5
020399, 020401 Soil from cleaning and washing fruit and vegetables only
A large amount of soil from cleaning and washing of fruit and vegetables is applied to land
under paragraph 7 exemptions. The soil is commonly separated from wash water by a
dissolved air flotation (DAF) system or similar prior to being applied to land. Another common
practice is that the soil is applied with vegetable peelings which may be mixed during the
preparation process or subsequent to the water treatment. Waste soil mixed with vegetable
peelings was not included in the assessment and it may be difficult to separate these wastes
where they are produced as part of the process. The soils may contain residues of pesticides
and fertilisers that have been applied to the crops. However, where these are dissolved they
will generally be removed during the DAF process.
Soil from cleaning and washing fruit and vegetables alone is often included under ―vegetable
processing waste‖ as in papers 82, 71 and 72. Imperial College (2006) undertook a study into
the application of industrial biowastes to land and looked at the composition of potato
washwater.
3.2.6
100101 Ash from wood chip boilers
Ash from wood chip boilers will generally have low trace metal contaminants, but this is
dependent on the quality control of the input material. Organic compounds will obviously be
lost in the incineration process, and ash will therefore have almost zero biodegradability
potential.
Ash will generally have an alkali pH (pH 10 – 12.5), and have some liming potential for
treatment of acidic soils. As any pathogens present in the feedstock would be destroyed in the
incineration process, pathogen potential will be extremely low, and therefore low risk.
Wood may be treated with copper chromium arsenic (CCA) treatments, but this use has been
limited since 2003 (WRAP, 2005). Arsenic is a volatile metal so it will mostly be lost in the
incineration process, but a portion will remain in the ash. Copper and chromium will
predominantly remain in the ash. However, CCA and creosote treated wood is classified as
hazardous waste, and should not be burnt in a standard wood chip boiler.
Wood can also be treated with a range of organic chemicals, but these will be lost to the
atmosphere in the incineration process.
WRc Ref: DEFRA8242/15419-0
May 2010
8
Defra
An EU Life project [70] looked at the recycling of wood chip boiler ash to forest communities
and demonstrated the agronomic, economic and environmental benefits of recycling ash to
woodland soils. These can be treated and turned into pellets etc. Work has also been done
by the Nordic Innovation Centre along the same lines as the EU Life project [75] with greater
emphasis on the physical and chemical properties of the ash and included its use in
agriculture.
The lower limit for application of ash is one tonne per hectare. This very low application rate
will help to mitigate any risk from metals present in the ash.
3.2.7
170506 Dredging spoil (other than those mentioned in 170505)
Dredging spoil is applied in large amounts to agricultural soil in the UK. In the original WRc
report (WR1103) it was found that dredging materials were one of the higher risk materials
applied to land, generally due to the very large quantities at which they are applied 1.
Dredgings are also very variable materials, and are likely to contain larger quantities of
contaminants downstream of settlements where a large number of industrial effluents are
discharged into the watercourse.
A small number of notifications were made for dredgings, particularly from park and garden
ponds and lakes. These appear to have lower levels of heavy metals than dredgings taken
from waterways in industrial areas. However, no information on organic contaminants in the
dredgings could be found. Certain potential organic pollutants (POPs) with toxic effects such
as poly-aromatic hydrocarbons (PAHs) have a high affinity for organic rich fines in sediments,
so where there is potential contamination of the water from which the dredgings are taken,
these may accumulate in the sediments. However, this does not appear to be a subject that
has been studied extensively, and analysis of POPs is not required for application under a
paragraph 7 exemption.
Most of the literature concerning dredging spoil application to land focuses on the effects of
marine sediments to land. The National Trust produced a report resulting from a workshop on
sediment management and dredging of lakes [54] in which they discuss spreading the
dredgings to land and the Broads Authority produced a paper on strategic dredging and
disposal sites [57]. Other than this, there is very little to be found on the disposal of dredging
spoil from inland conservation practices. Daniels et al [53] Aweto et al [55] and Babinchak et
al [56] all produced papers on certain effects of dredging spoil on agricultural land but these
are all applications outside the UK and Europe.
3.2.8
190599 Compost produced pursuant to a treatment described in the paragraph
numbered T23 or T26 of Chapter 2 only
The exemptions database holds a large amount of data for composting as it is widely spread
to land in the UK under paragraph 7 exemptions. Compost that meets the PAS100 quality
standard is no longer considered a waste and there is therefore no requirement to register a
paragraph 7 exemption in order to apply it to land. Compost applied to land under a paragraph
7 exemption is therefore non-PAS100 compost.
1
Under paragraph 7 exemption, dredging spoil may be applied at 1250 tonnes per hectare, whereas most other
materials are limited to 250 tonnes per hectare.
WRc Ref: DEFRA8242/15419-0
May 2010
9
Defra
In 2003, WRAP commissioned a literature review (Jones and Martin 2003) on human and
animal pathogens from green waste compost. This review found that composting at a
temperature of 55oC for at least 3 days was sufficient to eradicate most pathogens. Pathogens
are therefore considered low risk in composts from green wastes. In any case, composting will
reduce the risk of pathogens over the input material.
Human and animal pathogens from other materials may present a risk, for example animal
tissue waste, materials unsuitable for consumption or processing and kitchen waste. However,
as this material is subject to the Animal By-product Regulations, this should be sufficient to
negate any pathogen risk.
The nitrogen content of compost tends to be independent of the input material, as substances
with high nitrogen content will be broken down during the composting process. Applications
may be limited by NVZ limits (250 kg/ha) before the limit for the exemption is reached
(50 tonnes per hectare).
In addition, Defra has undertaken a review of the environmental and human health effects of
some waste management processes, which included the composting of green and kitchen
waste [39]. Monitoring and assessment papers were produced for growing media and soil
improvers [68, 46, 103], which include green waste compost. The ADAS project [84] on
application of compost and fertility of soil also holds information on the application and effect
of compost on soil. A paper on the merits, composition and application for vermicompost
(produced from a wormery) versus compost [62], showed the two substances had very similar
nutrient and trace metal compositions.
3.2.9
200108 Coffee grounds only
Coffee grounds contain nitrogen, principally in an organic form, not available to plants until it
has been broken down. Total N is less than 10 000 (about the equivalent of compost) and
phosphorus and potassium. Coffee grounds contain very low levels of trace metals, and would
therefore not be considered a risk from this point of view. No information was found on
pathogen risk, but it is considered that the risk is low.
There is very little information in the scientific literature on land spreading of coffee grounds.
At present, it is practiced on an industrial scale in the UK but not widespread across the
country.
3.2.10
020199 Milk from agricultural premises only
Application of waste milk to land is common under paragraph 7 exemptions. Milk must be
applied in a diluted form as it carries a very high biological oxygen demand (BOD) which can
have large environmental consequences to organisms in surface water. Application of milk
must therefore be carefully managed. Milk will contain very low levels of metals, and limited
amounts of nitrogen and phosphorus, but may add trace nutrients. Bacteria in unpasteurised
milk may benefit soil microbial populations.
WRc Ref: DEFRA8242/15419-0
May 2010
10
Defra
3.3
Risk scoring
Following assessment of data from exemption notifications and the literature review, the waste
materials can be scored using the scoring mechanism as used in project WR1103. The
wastes can then be ranked alongside other waste materials to show their relative risk.
The full scoring mechanism is reproduced in Appendix A. The risk score takes into account
the following factors:

Total amount of waste material spread nationally;

The total loading rate (tonnes per hectare) of the waste;

Nutrient content (principally nitrogen and phosphorus);

Heavy metal content;

Assessment of risk of microbial pathogens, organic pollutants and biodegradability (and
hence greenhouse gas emissions) of the waste.
For some of the wastes on certain parameters, estimates had to be made as it was not
possible to obtain information on the waste materials from paragraph 7 exemption notifications
as the materials are not applied under paragraph 7. In particular, the total amount of the waste
spread nationally is not known in many cases. The amount of waste spread per hectare has
been fixed at an application rate limit set in the exemption (50 t/ha for the majority of wastes).
In many cases, it is likely that smaller amounts of waste will be used, especially where limited
by NVZ limits.
The overall application of metals and nutrients is given in Table 3.2.
It can be seen that the concentrations of metals applied at this loading rate are very low for
the majority of the wastes. Generally nitrogen will be applied at less than the maximum rate
allowable under the nitrogen vulnerable zones legislation of 250 kg/ha, with the exception of
coffee grounds, compost and manures. It should be noted, however, that the figure for
manures is a percentile value based on a number of readings for manures and slurries from a
number of different animals, and total nitrogen concentration will vary considerably depending
on the exact source. Defra‘s Fertiliser Handbook (RB209) gives guidance on how these
materials should be applied and average nutrient values for different types of manure.
Using the full assessment methodology given in Appendix A, scores were derived using the
categories outlines above. Each category was given a score weighting, and Table 3.3 gives
the overall scores from this exercise. These scores were compared to scores given previously
in the earlier project (WR1103) which are outlined in Table 3.4.
WRc Ref: DEFRA8242/15419-0
May 2010
11
Defra
Table 3.2
Waste materials to be considered for assessment of environmental impacts
Waste material
EWC
Total waste Waste per
spread (t
hectare
000s)
(t/ha)
Zn kg/ha
Cu kg/ha
Ni kg/ha
Pb kg/ha
Cd kg/ha
Cr kg/ha
Hg kg/ha N (kg/ha) P (kg/ha)
Microbial
pathogen
risk
Organic
pollutant
Biodegradability
010102,
Chalk only
Unknown
50
low
low
low
low
low
low
low
low
low
N
N
N
15 700
50
11
3.7
0.35
0.16
0.02
0.32
-
448
154
Y
N
Y
50
low
low
low
low
low
low
low
low
low
Y
N
N
50
1.55
0.29
0.23
0.05
0.03
0.25
0.01
50
9
N
N
N
100101
1
-
-
-
-
-
-
-
low
v low
N
N
N
170506
100
56
7.91
2.88
4.98
0.07
0.97
0.01
229
105
Y
N
Y
010408,
170504
Farmyard and horse
manure only
020106
Shellfish shells from
which the soft tissue or
flesh has been
020202
removed only
Soil from cleaning and
washing fruit and
vegetables only
020399,
020401
Ash from wood chip
boilers produced
pursuant to an
operation described in
the paragraph
numbered U4 in this
Chapter only
Dredging spoil (other
than those mentioned
in 170505) generated
from the creation or
maintenance of
habitats, ditches or
ponds within parks,
gardens, fields and
forests only
WRc Ref: DEFRA8242/15419-0
May 2010
12
Defra
Waste material
EWC
Total waste Waste per
spread (t
hectare
000s)
(t/ha)
Spent compost from
Zn kg/ha
Cu kg/ha
Ni kg/ha
Pb kg/ha
Cd kg/ha
Cr kg/ha
Hg kg/ha N (kg/ha) P (kg/ha)
Microbial
pathogen
risk
Organic
pollutant
Biodegradability
020199
50
see
compost
see
compost
see
compost
see
compost
see
compost
see
compost
see
compost
-
-
N
N
Y
190599
50
7.6
3.1
1.2
3.9
0.03
1.0
0.007
295
94
N
N
N
190604
50
0.293
0.1125
0.0189
0.103
0.0004
0.019
0.0001
364
12.9
N
N
Y
pursuant to a treatment 190812
50
-
-
-
-
-
-
-
-
-
N
Y
Y
200108
50
1.0
0.84
0.6
0.16
0.007
0.22
0.002
346
91.8
N
N
Y
020199
0.22
0.40
0.43
0.03
0.03
0.03
0.0033
30
27
0.22
Y
N
Y
the growing of
mushrooms only
Compost produced
pursuant to a treatment
described in the
paragraph numbered
T23 or T26 of Chapter
2 only
Digestate produced
pursuant to a treatment
described in the
paragraph numbered
T24 or T25 of Chapter
2 only
Waste consisting of
biobed or biofilter
material produced
described in the
paragraph numbered
T32 of Chapter 2 only
Coffee grounds only
Milk from agricultural
premises only.
th
All concentrations are based on 90 percentiles for each individual waste category.
WRc Ref: DEFRA8242/15419-0
May 2010
13
Defra
Table 3.3
Waste materials to be considered for assessment of environmental
impacts
Risk Score
Risk rank (out of
85 wastes)
Farmyard and horse manure only
1.9
=30
Compost produced pursuant to a treatment
described in the paragraph numbered T23 or T26
of Chapter 2 only
1.9
=30
Digestate produced pursuant to a treatment
described in the paragraph numbered T24 or T25
of Chapter 2 only
1.9
=30
Soil from cleaning
vegetables only
1.5
=34
Spent compost from the growing of mushrooms
only*
1.5
=34
Milk from agricultural premises only
1.5
=34
Chalk only*
1.0
=41
Ash from wood chip boilers produced pursuant to
an operation described in the paragraph numbered
U4 in this Chapter only*
1.0
=41
Dredging spoil (other than those mentioned in
170505) generated from the creation or
maintenance of habitats, ditches or ponds within
parks, gardens, fields and forests only
1.0
=41
Coffee grounds only
0.6
55
Shellfish shells from which the soft tissue or flesh
has been removed only*
0.5
=58
Waste consisting of biobed or biofilter material
produced pursuant to a treatment described in the
paragraph numbered T32 of Chapter 2 only*
0.5
=58
Waste material
and
washing
fruit
and
The waste materials marked with an asterisk (*) did not have any registered notifications for
application of the material to land under a paragraph 7 exemption over 24 months (June 2007
– June 2009). For these waste materials, a literature review was carried out to assess
potential risks of application to land.
The lowest possible score using this scoring mechanism is 0.5. The higher scores are
generally due to a larger amount of the waste being spread in larger quantities nationwide
(>50 000 tonnes), as the risk assessment methodology gives a high weighting to wastes that
WRc Ref: DEFRA8242/15419-0
May 2010
14
Defra
are applied in large quantities. If this were discounted, all the waste materials would have a
risk score of <0.6.
Table 3.4 compares the change in scores between where waste was assessed for this project
and where they were assessed previously for project WR1103 (Defra, 2008).
Table 3.4
Comparison of risk scores between wastes applied under EPR 2007
Regulations and EPR 2009 Regulations
Risk score
LoW/EWC code
Wastes exempt under EPR
2007 Regs (WR1103)
Wastes exempt under EPR
2009 Regs (WR1120)
170506
7.0
1.0
170504
4.5
1.0
020399
3.8
1.5
190599
2.9
1.9
020202
2.0
0.5
190604
1.0
1.9
020106
0.8
1.9
The data shows that for the majority of wastes, the total risk score has been substantially
reduced. This is mainly due to more specific definitions given in the Environment Protection
Regulations 2009 (EPR2009), which has removed higher risk material from the categories e.g.
dredgings are now only included for lakes and ponds; dredgings from canals and rivers are
prohibited under the EPR2009.
There are inherent problems associated with making a direct comparison of the risk scores
attributed to each waste using the two aforementioned regulatory regimes. For example, in
this study (under EPR2009), digestates were recorded under LoW codes 19 06 04; 19 06 06;
03 03 05 and 19 06 99. In project WR1103, all waste categories were considered in terms of
their LoW code assigned by the applicant. WRc considered all wastes described as
'anaerobic digestates' for this study rather than limiting to only those which were registered
under 19 06 04, and therefore the categories are not completely analogous.
Risk scores for wastes 19 06 04 (anaerobic digestate) and 02 01 06 actually increased
compared with the previous study. For 19 06 04, more waste codes were considered than just
19 06 04, which affected the overall waste applied to land. It should be noted however that all
risk scores were still very low.
A key factor used within the scoring mechanism is the loading rates of the material in terms of
the tonnes per hectare (t/ha) applied to land. As the loading rate increases, so the loading of
nutrients and metals will increase, as do the potential risks.
In the revised exemption regime for low risk wastes, the maximum total application rate for the
waste is limited to 50 t/ha, with the exception of dredging materials and ash which are 100 t/ha
and 1 t/ha respectively. Previously, the loading rate of material had been limited to 250 t/ha for
WRc Ref: DEFRA8242/15419-0
May 2010
15
Defra
most wastes (although higher rates were allowed for dredging materials). This has the effect
that lower risk scores are obtained when considering the waste materials spread at lower
concentrations.
Another factor considered in the overall waste risk score is the total amount of waste spread in
England and Wales. The total amount of waste spread was either estimated from data
gathered in project WR1103, or taken from literature. As a large multiplier is used for the total
amount of waste applied score, this can have a major effect on the final waste score. In
addition, as some of the categories have changed slightly, this score will be altered from the
previous scores for project WR1103.
The limit given in the exemption is 50 t/ha for the material applied to land. In reality, limits from
the nitrogen vulnerable zones will limit the application of wastes before 50 t/ha could be
applied. For example, application of farm yard manures will often be limited on the basis of
their nitrogen content, and will not be applied at the rate of 50 t/ha.
WRc Ref: DEFRA8242/15419-0
May 2010
16
Defra
4.
CONCLUSIONS
The risks of applying the specified materials to land is considered to be low. All materials were
scored in the lower half of the list when ranked against all wastes being applied to land.
A number of the waste materials do have the potential to have elevated levels of some metals.
However, it is considered that the lower maximum limit of loading rate (tonnes per hectare of
waste spread) will mitigate these risks when the materials are applied to land.
Total nitrogen concentrations in these waste materials do have the potential to exceed
nitrogen vulnerable zone (NVZ) limits (250 kg/ha/y) where the materials are applied at the
maximum allowable loading rate of 50 tonnes per hectare. Total nitrogen concentration would
need to be monitored to avoid exceedances in accordance with good agricultural practice, and
may well limit application rates for materials with high nitrogen content.
The assessment was carried out using the 90th percentile chemical composition data for each
waste category. A high level of variability was seen for most wastes in the parameters for
which data was available. This was generally an artefact of the dry solids content of the waste
within a specific category. For example, farmyard manure can encompass manures and
slurries from a variety of different livestock and these differing materials would account for a
great deal of the observed variability.
When we compare the waste materials reviewed in this study with those considered
previously under project WR1103, most materials produce lower risk scores due to the more
limited types of waste allowed in each category. The lower scores were also in part due to the
lower application rate limit under the Environmental Permitting Regulations 2010 of 50 t/ha,
where under the previous exemption regime it had been 250 t/ha.
WRc Ref: DEFRA8242/15419-0
May 2010
17
Defra
WRc Ref: DEFRA8242/15419-0
May 2010
18
Defra
REFERENCES
1 - Eghball B, Power JF (unknown year), Management of Manure From Beef Cattle in
Feedlots and From Minor Classes of Livestock, US Department of Agriculture.
2 - Smith, C, Swanson, C (unknown year) Horse Manure Management, Virginia Cooperative
Extension, Publication 406-208.
3 - Clemson Extention (1996) Land Application of Animal Manure.
4 - Benny Rom H, Sorenson CG, (2001) Sustainable Handling and Utilisation of livestock
Manure From Animals to Plants, Proceedings, NJF-seminar No 320, Denmark, 16-19 January
2001.
5 - Guidance Note on the Control of Manure and Digestive Tract Content Under the EU
Animal By-Products Regulation (EC1774/2002) Version 5.
6 - Westendorf M, Krogmann U, (2004), Horses and Manure Fact Sheet, Rutgers Cooperative
Research and Extension, New Jersey Agricultural Experiment Station.
7 - Eghball, B, (2000), Nitrogen Mineralization from Field-Applied Beef Cattle Feedlot Manure
or Compost, SOIL SCI. SOC. AM. J., VOL. 64.
8 - DEFRA, (2009), Guidance for Farmers in Nitrate Vulnerable Zones, Standard values,
manure sampling protocol and glossary, www.defra.gov.uk/environment/water/quality/nitrate.
9 - DEFRA, (2002), Ammonia in the UK, HMSO.
10 - DEFRA (2008), Request from Britain (England, Scotland and Wales) for a Derogation To
The Livestock Manure Limit of 170 kg N per Hectare Per Year, HMSO.
11 - Shepherd M, Pearce B, Cormack B, Philipps L, Cuttle S, Bhogal A, Costigan P, Unwin P,
(2003), An Assessment of the Environmental Impacts of Organic Farming a review for DefraFunded Project OF0405, HMSO.
12 - DEFRA (2001) Managing Live Stock Manures, Booklets 1-3, HMSO.
13 - DEFRA (2009) Protecting our Water, Soil and Air, A Code of Good Agricultural Practice
for Farmers, Growers and Land Managers, HMSO.
14 - ADAS (2007) Investigating the Effectiveness of NVZ Action Programme Measures:
Development of a Strategy for England, Report for Defra Project No. NIT18.
15 - ADAS (2007) The Environmental Impact of Livestock Production, Review of Research
and Literature. Report for Defra FFG.
16 - DEFRA (2007), The British Survey of Fertiliser Practice Fertiliser Use on Farm Crops For
Crop Year 2007. ISBN 978-0-95525-693-6.
WRc Ref: DEFRA8242/15419-0
May 2010
19
Defra
17 - Gale P, (2002), Risk Assessment: Use of Composting and Biogas Treatment to Dispose
of Catering Waste Containing Meat, Final Report to the Department for Environment, Food
and Rural Affairs, WRc report no: 12842-0.
18 - DEFRA, (2001) Report on the 2001 Farm Practices Survey (England), HMSO.
19 - DEFRA (2007), Assistance on the Partial RIA Including Extended Nitrate Vulnerable
Zones in England, HMSO.
20 - UKROFS (2001) UKROFS Standards For Organic Food Production.
21 - DEFRA (2005) Defra Research in Agriculture and Environmental Protection Between
1990 and 2005: Summary And Analysis (ES0127), HMSO.
22 - Khiyami M, Masmali I, Abu-khuraiba M (2008), Composting a Mixture of Date Palm
Wastes, Date Palm Pits, Shrimp, and Crab Shell Wastes in Vessel System, Saudi Journal of
Biological Sciences 15 (2) 199-205.
23 - Tidmarsh WG, Merritt, JH, Bernier G, Joza J, Bastien-Daigle S (1986) Fish Waste
Disposal Practices and Options for Eastern New Brunswick, Canadian Industry Report of
Fisheries and Aquatic Sciences No 176.
24 - SEAFISH (2005) Legislative Requirements for the Disposal of Seafood Waste (draft
copy).
25 - Hayes LA, Richards R, Mathur SP (1994) Economic Viability of Commercial Composting
of Fisheries Waste By Passive Aeration, The Compost Council of Canada Symposium.
26 - Scottish Government (2005) Evaluation of Fish Waste Management Techniques,
http://www.scotland.gov.uk/Publications/2005/03/20717/52862.
27 - SEAFISH (2008) Using Autoclave Technology to Clean Up Shellfish Waste, Factsheet 407.08-Autoclaving.
28 - Irish Sea Fisheries Board (unknown year), Information Note on the Composting of
Organic Waste from Seafood Processing, Bord Iascaigh Mhara.
29 - SEAFISH (2006) Land Application of Shellfish By-products, Research & Development
Department.
30 - DEFRA (2007) Sustainable Production and Consumption of Fish and Shellfish
Environmental Impact Analysis, HMSO 9S6182.
31 - ADAS (2006) Review of the application of Shellfish By-Products to Land, SR586.
32 - Pattnaik S, Reddy MV, (2010), Nutrient Status of Vermicompost of Urban Green Waste
Processed by Three Earthworm Species—Eisenia Fetida, Eudrilus Eugeniae, and Perionyx
Excavatus, Applied and Environmental Soil Science Volume 2010, Article ID 967526.
33 - DEFRA, (2007) Advanced Biological Treatment of Municipal Solid Waste, HMSO.
34 - Bogner, J., M. Abdelrafie Ahmed, C. Diaz, A. Faaij, Q. Gao, S. Hashimoto, K. Mareckova,
R. Pipatti, T. Zhang, Waste Management, In Climate Change 2007: Mitigation. Contribution of
WRc Ref: DEFRA8242/15419-0
May 2010
20
Defra
Working Group III to the Fourth Assessment Report of the Intergovernmental Panel on
Climate Change [B. Metz, O.R. Davidson, P.R. Bosch, R. Dave, L.A. Meyer (eds)], Cambridge
University Press, Cambridge, United Kingdom and New York, NY, USA.
35 - Forestry Commission, (2006), Use of Sewage Sludges and Composts in Forestry,
Information Note.
36 - DEFRA (2005), Sources And Impacts Of Past, Current and Future Contamination of Soil,
SP0547 HMSO.
37 - Kupper T, Bucheli TD, Brändli RC, Ortelli D, Edder P, (unknown year), Dissipation of
Pesticides During Composting and Anaerobic Digestion of Source-Separated Organic Waste
in Full-Scale Plants.
38 - Planning Officers Society, (2002), On-Farm Green Waste Composting, An Advice Note.
39 - DEFRA (2004), Review of Environmental and Health Effects of Waste Management:
Municipal Solid Waste and Similar Wastes, © HMSO.
40 - DEFRA (2007) Mechanical Biological Treatment of Municipal Solid Waste, HMSO.
41 - DEFRA (2002) Municipal Waste Management Survey 2000/01 Results of the Survey,
HMSO.
42 - DEFRA (2003) Municipal Waste Management Survey 2000/01, HMSO.
43 - DEFRA (2005) Municipal Waste Management Survey 2003/04, HMSO.
44 - DEFRA (2008) The Open University Household Waste Study: Key findings from 2008,
HMSO.
45 - ADAS (2006) ADAS Science Review 2005–2006.
46 - DEFRA (2007) Monitoring of Peat and Alternative Products for Growing Media and Soil
Improvers in the UK 2007, Second biennial report by ADAS UK Ltd and Enviros Consulting
Ltd, HMSO.
47 - DEFRA (2006) Review of Targets For Recycling and Composting of Household Waste
and Their Interaction With Other Targets, HMSO.
48 - WRAP (2004), Increased Recycling of Quarry, Biodegradable, Green, Construction,
Demolition and Excavation Waste Streams Through the Manufacture of Soils. ISBN: 1-84405260-5.
49 - DEFRA (2007) Waste Strategy for England 2007 Annexes, HMSO.
50 - Fogg P, Fogg L, (2009) Biobeds for Treatment of Pesticide Waste and Washings,
Factsheet, Horticultural Development Company.
51 - SEAFISH (2005) Composting Trial for Seafish. SR 582.
52 - Preethu DC, Bhanu Prakash BNUH, Srinivasamurthy CA, Vasanthi BG, (2007) Maturity
Indices as an Index to Evaluate the Quality of Compost of Coffee Waste Blended with Other
WRc Ref: DEFRA8242/15419-0
May 2010
21
Defra
Organic Wastes, Proceedings of the International Conference on Sustainable Solid Waste
Management, 5 - 7 September 2007, Chennai, India. pp.270-275.
53 - Daniels WL, Whittecar GR, Carter III CH, (2007) Conversion Of Potomac River Dredge
Sediments to Productive Agricultural Soils Paper, presented at 2007 National Meeting of
Amer. Soc. Of Surface Mining and Reclamation, Gillette WY, June 2-7, 2007. ASMR 3134
Montevesta Dr., Lexington KY.
54 - National Trust (2002), Sediment Management & Dredging in Lakes, A report based on a
workshop held at Arlington Court, Devon March 2002.
55 - Aweto AO, Oyegunwa, O (2000) Trace element status of dredged spoils and
hydromorphic soil in the Mahin area, south western Nigeria, Land Contamination &
Reclamation, 8 (4), 2000.
56 - Babinchak Ja, Graikoski Jt, Dudley S, Nitkowski Mf (1977) Effect of Dredge Spoil
Deposition on Faecal Coliform Counts in Sediments at a Disposal Site, Applied And
Environmental Microbiology, Vol. 34, No. 1, p. 38-41.
57 - Broads Authority (2009), Strategic Dredging Disposal Sites.
58 - Casebow A, (2001), Sustainable Farming in Guernsey, Journal of La Societe
Guernesiaise.
59 - DEFRA (2004) Impacts of Cap Reform Agreement On Diffuse Water Pollution From
Agriculture, HMSO.
60 - Uzun I, (2004) Use Of Spent Mushroom Compost in Sustainable Fruit Production, Journal
of Fruit and Ornamental Plant Research vol. 12 2004 Special Ed.
61 - Özgüven AI, (1998), The Opportunities of Using Mushroom Compost Waste in Strawberry
Growing, Tr. J. of Agriculture and Forestry 22 601-607.
62 - Smith CJ, Bond, WJ, Wang W, (1999), Waste Free: "Vermicompost" to Improve
Agricultural Soils, CSIRO Land and Water Technical Report 23/99.
63 - Polat E, Uzun HB, Topçuo lu B, Önal K, Naci Onus M, Karaca M, (2009) Effects of Spent
Mushroom Compost on Quality and Productivity of Cucumber (Cucumis sativus L.) Grown in
Greenhouses, African Journal of Biotechnology Vol. 8 (2), pp. 176-180.
64 - Amy Suess, Jennifer Curtis (2006), Value-Added Strategies for Spent Mushroom
Substrate in BC, British Columbia Mushroom Industry.
65 - United Nations Economic and Social Commission For Asia and The Pacific (Unknown
Year), Training Manual On Mushroom Cultivation Technology, Asian and Pacific Centre For
Agricultural Engineering And Machinery (Apcaem).
66 - Various (unknown Year) Spent Mushroom Substrate, Scientific Research and Practical
applications, www.mushroom-sms.com.
68 - DETR (2000) Monitoring and Assessment of Peat and Alternative Products for Growing
Media and Soil Improvers in the UK (1996–1999), HMSO.
WRc Ref: DEFRA8242/15419-0
May 2010
22
Defra
69 - FERA, (2008) Code of Practice for the Management of Agricultural and Horticultural
Waste, HMSO.
70 - EU (2006) From Extraction of Forest Fuels to Ash Recycling, EU Life Project.
71 - Hailong Wang, (2007) Good Management Practices for Land Application of Vegetable
Processing Wastes, The Joint Forces of CSIRO and SCION.
72 - C.S. Papdopl, J.D. Nolan, (unknown year) Environmentally Acceptable Disposal of
Wastes From the Vegetable Processing Industries.
73 - Department of Environmental Protection (2006) Maine Solid Waste Management Rules:
Chapter 418 Beneficial Use of Solid Wastes.
74 - Rona Pitman, (unknown year), Wood Ash Use in Forestry, A Review of the Environmental
Impacts.
75 - Nina Haglund and Expert Group (2008), Guideline For Classification of Ash From Solid
Biofuels and Peat Utilised For Recycling and Fertilizing in Forestry and Agriculture, Nordic
Innovation Centre.
76 - Risse, M (2002) Best Management Practices for Wood Ash as Agricultural Soil
Amendment.
77 - Frost P, (2005), Opportunities for Anaerobic Digester CHP Systems To Treat Municipal
and Farm Wastes, AFBINI.
78 - University of Plymouth (2005). Composting Food Wastes: 1. Scientific Aspects. [online].
Available from:
http://www.research.plymouth.ac.uk/pass/Research/Scientific%20aspects%20of%20food%20
waste%20composting.pdf [Accessed 17/03/2010].
79 - DEFRA (2005) New Technologies Demonstrator Programme Catalogue of Applications,
HMSO
80 - DEFRA (2002) Utilisation of Eggshell Waste From UK Egg Processing and Hatchery
Establishments, HMSO
81 - David Tompkins (2006) Organic Waste Treatment Using Novel Composting
Technologies, Summary Report, http://www.science.plym.ac.uk/pass/
82 - H Rigby and S R Smith, (2009) Agronomic Benefit of Industrial Biowastes (WR0214),
Imperial College of Science, Technology and Medicine.
84 - ADAS (2007) Soil Quality and Fertility Annual Report 2006, ADAS.
85 - SORP (unknown) Technical Briefing Note 1 Recycling Organic Materials to Land, The
Facts.
86 - Steven Humphries, Brian Chambers, Fiona Nicholson, Steven Anthony and Chris Procter,
Agricultural Landbank, Organic ‗Waste‘, A National Capacity Estimator (ALOWANCE).
87 - DEFRA (2005) Soil Organic Matter as an Indicator of Soil Health.
WRc Ref: DEFRA8242/15419-0
May 2010
23
Defra
88 - SAC and ADAS (2006) Nutrient Value of Digestate from Farm-Based Biogas Plants in
Scotland. Report for Scottish Executive Environment and Rural Affairs Department ADA/009/06.
89 - Tucker P (2005) Co-Composting Paper Mill Sludges With Fruit and Vegetable Wastes,
The University of Paisley.
90 - MAFF (2000) Fertiliser Recommendations for Agricultural and Horticultural Crops
(RB209), HMSO.
91 - ADAS (unknown) The Effects of Reduced Tillage Practices and Organic Material
Additions on The Carbon Content of Arable Soils, Scientific Report for Defra Project SP0561,
HMSO.
92 - UKWIR (unknown) Application of Phosphorus In Industrial Biosolids to Agricultural Soils,
(UKWIR Project SL02 B).
93 - DEFRA (2003) Development of operational Guidelines to Support Safe Application of
Biosolids to Agricultural Land, PE0208.
94 - Michael Reid (2007) Waste Data Report: Supporting the East Sussex and Brighton &
Hove Waste and Minerals Development Framework Draft Report – Stage 1, East Sussex
County Council and Brighton & Hove City Council.
95 - CL:AIRE (2008) The Definition of Waste: Development Industry Code of Practice,
DRAFT.
96 - BAA (2006) The Deposit of Inert Wastes.
97 - CL:AIRE (2008) Definition of Waste and Land Development Frequently Asked Questions
on the Definition of Waste: Development Industry Code of Practice, CL:AIRE.
98 - Surrey County Council (unknown) Surrey Replacement Minerals Local Plan Background
Paper – Chalk, Peat, and Hoggin.
99 - Quarry Products Association (2006), The Need For Inert Wastes to Restore Aggregate
Mineral Workings, Position Statement from the Quarry Products Association.
100 - East Sussex and Brighton & Hove Minerals Local Plan - Adopted 18 November 1999.
103 - DEFRA (2006) Monitoring and Assessment of Peat and Alternative Products for
Growing Media and Soil Improvers in the UK (2005), HMSO.
104 - Fabien Monnet,(2003) An Introduction to Anaerobic Digestion of Organic Wastes, Final
Report, Remade Scotland.
105 - WRAP (2009) Anaerobic Digestate Partial Financial Impact Assessment of the
introduction of a Quality Protocol for the Production and Use of Anaerobic Digestate, HMSO.
106 - DTI (1997) Energy from Biomass, Summaries of the Biomass Projects Carried out as
Part of the DTI's New and Renewable Energy Programme Volume 4: Anaerobic Digestion for
Biogas.
WRc Ref: DEFRA8242/15419-0
May 2010
24
Defra
107 - Humphries (2007) Agricultural Landbank, Organic ‗Waste‘, A National Capacity
Estimator (ALOWANCE) 2007, Humphries, S, Chambers, B, Nicholson, F, Anthony, S, and
Procter, C.
108 - Dass (2003) Utilization of Waste Chalk From Fertilizer Industry as Filler in Building
Materials, Arjun Dass, R. S. Srivastava, Jaswinder Singh Building and Environment, Volume
28, Issue 3, July 1993, Pages 231-234, ISSN 0360-1323, DOI: 10.1016/0360-1323(93)900282.
109 - Hoon Lee (2007) Effects of Oyster Shell on Soil Chemical and Biological Properties and
Cabbage Productivity as a Liming Material, Chang Hoon Leea, Do Kyoung Leeb, Muhammad
Aslam Alia and Pil Joo Kima, Division of Applied Life Science, Graduate School, Gyeongsang
National University, Jinju 660-701, Republic of Korea Plant Science Department, South
Dakota State University, Republic of Korea Institute of Agriculture and Life Sciences,
Gyeongsang National University, Republic of Korea
110 - WRAP (2005) Options and Risk Assessment for Treated Waste Wood.
WRc Ref: DEFRA8242/15419-0
May 2010
25
Defra
WRc Ref: DEFRA8242/15419-0
May 2010
26
Defra
APPENDIX A
METHODOLOGY FOR ASSESSING IMPACTS AND
PRIORITISING HIGH RISK WASTES
INTRODUCTION
Identifying high risk wastes by assessing their environmental impact is a key step in the
assessment of impact of waste spread to land under paragraph 7 exemptions from
Environmental Permitting.
To categorise waste types by their overall risk presented for each waste type, a methodology
has been developed to attribute a risk score to each waste, allowing comparison of waste
types.
In order to fully characterise the risk presented from each waste, the two main factors which
must be considered are:
Amount of waste spread (total and amount per hectare) - the total amount spread of any
waste in England and Wales, and the average loading per hectare.
Properties of the waste – Characteristics of the waste, broken down in to the following six
categories:






Metal concentration in the waste (Zn, Pb, Cu, Ni, Cd, Hg)
Nutrient content (N and P)
Biodegradability/ C:N ratio (Greenhouse gas potential)
Pathogen potential
Organic pollutants
Reported pollution incidents relating to waste type.
As detailed below, a score will be derived for both the amount of waste spread and the
properties of the waste, and turned into multiplying factors to obtain the overall risk score.
This assessment is a first-pass assessment and necessarily does not take into account every
possible characteristic of the waste, and is, in part, qualitative. As such, we will examine the
data in more detail for each waste before a final priority list is decided upon.
METHODOLOGY
The overall risk for each waste is given by the following calculation.
Overall risk = Waste properties risk score x Waste spread risk score
Where:
Waste spread risk score = Total waste score x waste per hectare score
Waste properties risk score = Z x Y x X x W x V x U
Where Z to V are equal to either 1.0 or 1.25:
WRc Ref: DEFRA8242/15419-0
May 2010
27
Defra
Z = Metal concentration in the waste (Zn, Pb, Cu, Ni, Cd, Hg)
Y = Nutrient content (N and P)
X = Biodegradability/ C:N ratio (Greenhouse gas potential)
W = Pathogen potential
U = Organic pollutants
V = Reported pollution incidents relating to waste type
And Z to U = 1.25 or 1
The calculation is explained further over the following sections.
Waste spread risk score
Total waste score
The total amount of each waste type spread to land is considered to be the most important
factor when considering overall environmental risk of the waste. We therefore propose to
weight it accordingly, with the highest multiplying factors of any category. Each waste will be
given a score of 1 – 3 as follows:
Mass spread (t)
0 – 10 000
10 001 – 50 000
>50 000
Score
1
2
3
The mass spread figure is the sum in tonnes of each waste type spread per year.
Waste per hectare score
The average loading per hectare is also key in terms of environmental risk. The wastes will be
divided in to three categories depending on the average amount spread per hectare, and
scored as follows:
Mass spread (t/h)
0 - 100
101 - 200
>201
Score
0.5
1
1.5
The total waste score and the waste per hectare score are then multiplied together to give a
waste spread risk score.
WRc Ref: DEFRA8242/15419-0
May 2010
28
Defra
Waste properties risk score
The six waste properties will also be considered as part of the assessment. To simplify the
calculations as far as possible, each waste is placed in one of two risk groups:


Low risk (score: 1)
High risk (score: 1.25)
The multiplying factor for each category are then multiplied together, to produce the over
waste properties risk score.
Heavy metal content
The six metals for which analysis is required as part of an application for a paragraph 7
exemption are:






Zinc
Lead
Cadmium
Nickel
Mercury
Copper
Concentration of these metals will form the basis of the calculation for metals contents, which
will be obtained from paragraph 7 application forms.
We have chosen to compare levels of metals to threshold values set in the compost standard
BSI PAS100:2005 levels. These limits were chosen as they are absolute limits, and were set
in order to protect human health and the environment when compost is applied to land. The
PAS100 limits are as follows:
Metal
Threshold Value (mg/kg DM)
Zinc
400
Lead
200
Cadmium
1.5
Nickel
50
Mercury
1.0
Copper
200
The 90th percentile of metal concentrations for the dataset for each waste will be determined.
This will give an indication of the range of data, while discounting any outliers.
Where the amount of metal present in the waste is less than the threshold value, it will be
given a score of zero. Where the concentration is greater than the threshold value, a score will
be given based on the calculation of the ratio - concentration: threshold value. For example,
for a waste that has a Zn concentration of 600 mg/kg DM, the score for Zn will be 1.5.
WRc Ref: DEFRA8242/15419-0
May 2010
29
Defra
This calculation is repeated for each metal to give an overall metals score:
Zn score + Pb score + Cd score + Ni score + Hg score + Cu score = overall metals score
Where the overall metals score is <3, the waste will be considered low risk with respect to
metals and given a multiplying factor of x1. Where the score is >3 it will be considered there is
some degree of risk, and a multiplying factor of x1.25 applied. This will identify where
individual metals have a high concentration, or where there are a range of metals with slightly
elevated concentrations.
Nutrients
A similar approach will be taken for scoring the nutrient quantity in each waste to the approach
it is used for. Nitrogen and phosphate will be considered in the assessment of nutrient
content, and will be compared against 5% levels of both nitrogen and phosphorus. Again,
where N and P are present below these threshold levels, a score of 0 will be given, and where
it is over, a score equal to the ratio of concentration {nutrient: threshold value} will be given,
and the two scores from N and P summed:
N score (where N > 5% DM) + P score (where P > 5% DM) = overall nutrients score.
Where the overall nutrients score is >1.5, a multiplying factor of x1.25 will be applied. Where
the overall nutrients score is <1.5, the multiplying factor will be x1.
Microbial pathogens, organic pollutants and biodegradability (greenhouse gas potential)
The above three categories are grouped together as there is very little data available from the
literature, and it is expected that little data will be available from the application forms. The
initial review of paragraph 7 application forms has similarly shown very few operators have
provided data of this type of analysis.
An approach similar to that above will be taken where wastes which have a perceived risk in
relation to these categories will be given a multiplying factor of x1.25, and those with a smaller
risk will be given a multiplying factor of x1.
The process of applying these multiplying factors will necessarily be subjective due to the lack
of available data for waste materials.
Pollution incidents
The number of pollution incidents reported to the Environment Agency for any particular waste
stream will be obtained from Environment Agency systems. We will then score the incidents
for each waste as follows:


Non-serious incident (CICS category 3 or 4) = 1 point
Serious incident (CICS category 1 or2) = 3 points
The total number of points for each waste will then be summed. If the total points score for
any particular waste is greater than 3, it will be given a multiplying factor of x1.25 and if it is
less than 3, a multiplying factor of x1 will be applied.
WRc Ref: DEFRA8242/15419-0
May 2010
30
Defra
FINAL SCORING
Following determination of the multiplying factor for each category, these are applied to the
waste scores and the overall risk score is determined. A spreadsheet tool has been developed
to obtain the score for each waste once the subjective risk assessment has been carried out.
Criteria for each category is summarised below.
Waste properties
Waste spread
Group
Category
Multiplying factor
Criteria
Total tonnes spread in
England and Wales
Grouped in to <10 000
t/y (x1), 10 000 –
50 000 (x2) or
>50 000 (x3)
Based on total waste spread for each
waste
Average loading rate
(t h-1)
Grouped in to <100
t/ha (x0.5), 100 – 200
t/h (x1), >200 t/h
(x1.5)
Based on average loading rate
Metal concentration in
the waste (Zn, Pb, Cu,
Ni, Cd, Hg)
Score <3 (x1) or score
>3 (x1.25)
Individual metal concentrations divided
by respective PAS100 limits. Where
ratio >1, ratios are summed to give
overall score.
Nutrient content (N and
P)
Score <1.5 (x1) or
>1.5 (x1.25)
N and P concentration for each waste
divided by 5%. Where this ratio >1,
ratios are summed
Biodegradability/ C:N
ratio (Greenhouse gas
potential)
No risk (x1) or Some
risk (x1.25)
Qualitative assessment
Pathogen potential
No risk (x1) or Some
risk (x1.25)
Qualitative assessment
Organic pollutants
No risk (x1) or Some
risk (x1.25)
Qualitative assessment
Reported pollution
incidents relating to
waste type
Score <3 (x1) or score
>3 (x1.25)
Where serious pollution incident
reported score 2, non-serious = 1.
Scores are summed for each waste
WRc Ref: DEFRA8242/15419-0
May 2010
31
Defra
WRc Ref: DEFRA8242/15419-0
May 2010
32
Defra
APPENDIX B
DATA SUMMARIES FOR WASTE CATEGORIES
General process
category
FYM
Compost
Dredgings
Veg washings
Parameter
Zn as applied (wet
Cu as applied (wet
Ni as applied (wet
Pb as applied (wet
Cd as applied (wet
Cr as applied (wet
Hg as applied (wet
weight) mg/kg
weight) mg/kg
weight) mg/kg
weight) mg/kg
weight) mg/kg
weight) mg/kg
weight) mg/kg
Total N as
Total P as
applied (wet
applied (wet
weight) mg/kg
weight) mg/kg
Minimum
0.8
0.2
0.02
0.01
0.0007
0.01
-
8.4
40
10th Percentile
0.8
0.2
0.02
0.02
0.0013
0.01
-
18
55
Mean
4.1
1.5
0.13
0.07
0.01
0.15
-
218
104
Median
1.7
0.8
0.1
0.0
0.0
0.0
-
146
103
90th Percentile
11
3.7
0.35
0.16
0.02
0.32
-
448
154
Standard deviation
4.1
1.6
0.2
0.1
0.0
0.3
-
225
55
Maximum
11
5.5
0.6
0.2
0.0
1.3
-
851
171
n
16
17
16
16
16
16
-
19
4.0
Minimum
0.008050
0.004500
0.004750
0.001400
0.000250
0.011350
0.000478
0.1
0.01
10th Percentile
1
0.5
0.3
0.075
0.005
0.2
0.0021
56
1.58
Mean
7
2
1
11
0.020
0.8
0.0058
348
47
Median
4
2
1
2
0.016
0.7
0.0043
381
46
90th Percentile
20
3.52
1.27
45
0.04
1.62
0.01
563
93
Standard deviation
8
2
0.50
20
0.01
0.55
0.01
186
38
Maximum
33
14
3
76
0.05
1.85
0.03
645
174
n
63
64
55
56
55
50
55
67
75
Minimum
3.1
2.0
0.9
0.9
0.02
0.61
0.00
132
36
10th Percentile
4.1
2.5
0.9
1.3
0.02
0.62
0.00
143
44
Mean
25
5.2
1.8
3.1
0.04
0.77
0.01
186
75
Median
12
5
1
3
0.04
0.64
0.01
186
75
90th Percentile
56
7.91
2.88
4.98
0.07
0.97
0.01
229
105
Standard deviation
33
3
1
2
0
0
0
77
54
Maximum
73
9
3
6
0
1
0
240
113
n
4
3
3
4
4
3
4
2
2
Minimum
0.01
0.00
0.00050
0.00050
0.00025
0.00050
0.0000500
0.40
0.38
10th Percentile
0.01
0.00
0.005
0.001
0.000250
0.002
0.000060
1
0.5
Mean
0.37
0.11
0.13
0.020
0.009
0.07
0.0020
21
2.8
Median
0.03
0.03
0.05
0.013
0.005
0.03
0.0013
12
1.4
90th Percentile
1.55
0.29
0.23
0.05
0.03
0.25
0.01
50
9
Standard deviation
0.7
0.2
0.3
0.0
0.0
0.1
0.0
27
3
Maximum
2.5
0.5
1.0
0.1
0.1
0.3
0.0
109
12
n
46
46
43
37
34
38
23
46
45
WRc Ref: DEFRA8242/15419-0
May 2010
33
Defra
General process
category
AD
Coffee
Milk
Parameter
Zn as applied (wet
Cu as applied (wet
Ni as applied (wet
Pb as applied (wet
Cd as applied (wet
Cr as applied (wet
Hg as applied (wet
weight) mg/kg
weight) mg/kg
weight) mg/kg
weight) mg/kg
weight) mg/kg
weight) mg/kg
weight) mg/kg
Total N as
Total P as
applied (wet
applied (wet
weight) mg/kg
weight) mg/kg
Minimum
0.22
0.08
0.0098
0.00240
0.00015
0.00640
0.00005
77
3.0
10th Percentile
0.22
0.08
0.010
0.00
0.00015
0.01
0.00005
235
3.0
Mean
0.24
0.10
0.012
0.03
0.00020
0.01
0.00009
303
8.3
Median
0.22
0.11
0.010
0.00
0.00015
0.01
0.00010
304
8.0
90th Percentile
0.29
0.11
0.019
0.10
0.00035
0.02
0.00010
364
13
Standard deviation
0.0
0.02
0.004
0.05
0.00009
0.01
0.00002
64
3.1
Maximum
0.3
0.11
0.02
0.10
0.00035
0.02
0.00010
364
13
n
8
8
8
8
8
8
8
23
23
Minimum
0.43
0.30
0.15
0.01
0.0008
0.08
0.0006
285
39
10th Percentile
0.43
0.30
0.15
0.01
0.0008
0.08
0.0006
285
39
Mean
0.48
0.32
0.42
0.03
0.0016
0.11
0.0007
322
40
Median
0.51
0.30
0.60
0.01
0.0008
0.14
0.0006
347
40
90th Percentile
0.51
0.36
0.60
0.07
0.0030
0.14
0.0010
347
40
Standard deviation
0.0
0.0
0.2
0.0
0.0
0.0
0.00024
34
0.2
Maximum
0.5
0.4
0.6
0.1
0.0
0.1
0.00099
347
40
n
5
5
5
5
5
5
5
5
5
Minimum
0.0003
0.0003
0.0007
0.0003
0.00003
0.0019
0.00001
7.0000
0.4
10th Percentile
0.0003
0.0003
0.0039
0.0003
0.0000
0.0035
0.00001
8.5
0.4
Mean
0.10
0.10
0.10
0.01
0.01
0.02
0.0016
21
7.6
Median
0.10
0.01
0.02
0.0039
0.0003
0.03
0.0013
16
4.2
90th Percentile
0.22
0.40
0.43
0.03
0.03
0.03
0.0033
30
27
Standard deviation
0.10
0.14
0.15
0.02
0.02
0.01
0.0014
11
8
Maximum
0.35
0.40
0.43
0.05
0.05
0.05
0.01
53
27
n
21
20
19
20
19
20
18
22
21
WRc Ref: DEFRA8242/15419-0
May 2010
34